Ever since the creative innovation of organum during the middle ages (organum being the simultaneous singing of two melodic lines a fourth or a fifth apart) harmony has been one of the distinctive characteristics of almost all forms of western music. Today harmony has evolved into a complex manifestation of art and science as embodied, for example, in music theory. In practice, one of these manifestations is the playing of chords on several instruments, notably keyboards and the large family of string instruments. There is a very large number of such chords in the musical repertoire, ranging from simple chords having only two constituent tones or major and minor chords composed of three tones to complex chords used in jazz which may have been seven or even more constituent tones.
Thus, it will be apparent that it takes time for an interested person-even a gifted musician-to develop and train the ear to become harmonically sensitive. Yet this process is certainly worthwhile, for music, like all art, is ultimately meant to be immensely pleasing and enriching experience.
Accordingly, many techniques have been invented to help among the path to the appreciation of harmony as well as other facets of music. The most important technique is of course the translation of music into written visual symbols or notation, along with many more or less elaborate visual aids. The present invention belongs to the latter class.
The visual aids proposed in the past by the prior art are generally deficient in that they are difficult to read, difficult to handle or too generic. For example, the Canadian Pat. No. 773,425 issued to Y. A. Gaillard on Dec. 12, 1967 teaches an extensively detailed layout including several discs, a slide "memory" arranged in the so-called "circle of fifths" and an "album" provided with a pocket 8 (see FIG. 5) for storing unused discs.
Another patent, issued in the United States to M. L. Clopton on Feb. 20, 1951 and bearing U.S. Pat. No. 2,542,235 discloses a dial having two printed faces wherein the circumference of each face is delineated again according to the circle of fifths. The mechanism also includes a face plate provided with a plurality of windows in which appear a variety of musical data as the dial is rotated. A pointer attached to the dial is adapted to move in an arc made therefor in the face plate. Although simplified in relation to prior devices, this mechanism is still apt to create confusion.
Still another U.S. Pat., No. 2,649,008 issued to Fred Bova et al on Aug. 18, 1953 features two discs and a slide rule sandwiched therebetween. Again, there are several windows from which desired musical data may be obtained. This chart is perhaps not too generic, being specifically limited to stringed instruments, but is still relatively complicated and difficult to read.